Abstract

The qualitative analysis of coordinate transformations, from the view-point of the reciprocity principle, allows the derivation of not only the Lorentz's transformation (LT), involving inertial motions, but also of a non-reciprocal transformation (N-LT), here called the Co-Lorentz transformation (Co-LT), valid for non-uniform motions. Consequently, relativistic kinematics is a double faced theory: it assumes either the LT, when the motion is inertial, or the Co-LT when the motion is non-inertial. The complementarity of LT and Co-LT implies the complementarity of the corresponding Einstein special relativity (ESR) and a non-reciprocal counter-part (N - ESR), here called Co-Einstein special relativity (Co-ESR). By neglecting gravitational effects, a relativistic electrodynamics, founded on Co-ESR is elaborated. Adding to the classical LT and ESR their corresponding complementary versions Co-LT and Co-ESR, a complete view of the special relativity of physical reality is obtained.

Motto: Extended Special Relativity is like the Moon which shows us only one of her faces: it is Einstein's SR. The hidden face is Hertz's SR.